It was only a week ago that President Trump said publicly that it was time to bring U.S. troops home from Syria. Now he's contemplating military action against the Syrian regime in retaliation for a suspected chemical weapons attack. It's unclear how robust that military response will be. It's also unclear what it would mean for the larger U.S. strategy in Syria.

CORNISH: At this time, what is the president's strategy on Syria as you understand it?

LIASSON: I don't know if he has a strategy. I think he has some inclinations, one of which is that there's a red line - chemical weapons should not be used. And if they are, he will respond. The second one is that he wants to defeat ISIS and then get out of Syria. And he thinks that other countries should be responsible. In this case of course those other countries could be Russia, Iran and the Syrian regime. That is in contradiction to the stated strategy of his military advisers like the secretary of defense who say the hard work is just beginning. We have to stay in Syria to stabilize it. So on the one hand he's kind of hawkish, on the other he's a noninterventionist.

CORNISH: If this administration chooses military action, how would that change the equation?

LIASSON: Well, that's a really good question 'cause we don't know exactly what the U.S. will do. We know that a year ago he made a limited strike on a Syrian airfield after a chemical weapons attack. We know that his new national security adviser, John Bolton, in the past was against President Obama making limited strikes against Syria 'cause he didn't think that it would do the trick. He thought it was just a meaningless slap on the wrist. But we don't know if he'll go - President Trump will go so far as to attack the Syrian Air Force, try to demolish it. That would risk a confrontation with Russia. So we're waiting to find out what he wants to do. And we know that he has canceled a trip to Latin America this weekend in order, according to the White House, to oversee the response to Syria.

CORNISH: You mentioned John Bolton being new. It's actually his second official day on the job as national security adviser. Have there already been changes?

LIASSON: Yes, there has. The spokesman for the National Security Council, Michael Anton, has been fired or at least encouraged to resign. And then Tom Bossert, the deputy national security adviser and the top homeland security adviser to the president, also has resigned. Just this weekend at a conference in Georgia, Bossert didn't seem to have any notion that his days and hours were numbered. Here's what he said.

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TOM BOSSERT: I think at this point we've reached what seems to be a decent stability point. And I'm pretty comfortable with the president's view of that. But it's a little different.

SUZANNE KELLY: So no more exits, departures, shifting around in the - is that what you're saying?

BOSSERT: No. I just...

KELLY: (Laughter).

BOSSERT: I just feel...

KELLY: I thought that's what I heard. OK (laughter).

BOSSERT: I feel comfortable for today. And...

KELLY: (Laughter). Noted.

LIASSON: So comfortable for today. But I should say this isn't like Donald Trump making big changes by firing people. This is John Bolton, new national security adviser, coming in, cleaning house at the NSA. He wants his own people there.

CORNISH: One more topic. The reporting has been that the president was visibly angry last night when talking about the FBI raid on his longtime personal lawyer, Michael Cohen. Of course the president went on to trash special counsel Robert Mueller's investigation and senior Justice Department officials. That includes his own attorney general. Has this blown over?

LIASSON: I don't think so. I think it's still a live issue. The president is still pretty angry. Sarah Sanders says not only that the White House believes the president has the authority to fire Mueller, something she's said in the past, but in the past she's always issued a qualifier saying, well, the president doesn't intend to do that or he isn't contemplating do that - doing that. She did not issue the qualifier today. And we've had a little polite pushback from Republicans in Congress, Senate Majority Leader Mitch McConnell saying Mueller should be allowed to finish his investigation, John Cornyn saying he should issue a report, and Senator Chuck Grassley saying thinking about firing him would be suicide.